Dispenser and applicator for liquid weed exterminators



Mar h 55 R. J. LUNN E+ AL 2,703,192

DISPENSER AND APPLICATOR FOR LIQUID WEED EXTERMINATORS Original FiledFeb. 5, 1951 Zhwentors Gttornegs United States Patent DISPENSER ANDAPPLICATOR FOR LIQUID WEED EXTERMINATORS Robert J. Lunn and Wilfred W.Lowther, St. Paul, Minn., assignors to Donaldson Company, Inc., St.Paul, Minn., a corporation of Delaware Original application February 5,1951, Serial No. 209,381. Divided and this application February 15,1952, Serial No. 273,027

3 Claims. (Cl. 222--318) Our invention relates to improvements indevices for dispensing weed exterminating liquids and applying the sameto undesirable lawn weeds, particularly those of the broad leaf variety,such as dandelion, plantain, chick- Weed and the like. It is anestablished fact that such lawn weeds can very effectively be controlledby application thereto of the chemical 2,4-D, dichlorophenoxyaceticacid. In controlled solution, this chemical is a growth stimulant, butin greater concentration, it causes such rapid growth that the plantroot system bursts and the plant dies. For effective extermination, thischemical is mixed with water and applied directly to the leaf surfacesof the lawn weeds. Actually, the chemical 2,4-D, in sufficientlyconcentrated solution to kill undesirable broad leaf weed plants, willalso destroy most any other plants or grass with which it comes incontact, and as a consequence, effective control of undesirable weedplants requires localized or controlled application.

In view of the above, it is an object of the invention to provide animproved device of the class described whereby accurately controlledmeasured quantities of weed-destroying liquid may be locally applied,quickly and easily, to undesirable lawn weeds or plants with a minimumof injury to desirable plant life, such as domestic grass, clover andthe like.

Another important object of the invention is the provision of a deviceof the class described, involving a liquid reservoir for storage of theweed exterminating liquid or the like and a pump mechanism forcontrolled dispensing of the liquid, of an improved construction wherebyleakage or seepage of the stored liquid, during idle periods of thedevice, is eliminated. inthis connection, it may be said that ourinvention provides simple and effective means whereby the liquidreservoir of the device is automatically sealed against leakage orseepage of the contained liquid during idle periods of the device, sothat a relatively large quantity of a suitable weed exterminating liquidor the like may be stored in the device for long periods without loss.

Another important objective of the invention is the provision of simpleand inexpensive means for accomplishing the important objective, lastabove noted, without resorting to costly close-working tolerances of themovable parts.

Other objectives of the invention are the provision of a device of theclass described, which is highly etficient in operation, is veryconvenient to use, has a minimum of parts, has exceptionally long lifeand can be produced at a very low cost.

This application is a division of our co-pending application, Serial No.209,381, filed February 5, 1951.

The above and other highly important objects and advantages of theinvention will be made apparent from the following specification, claimsand appended drawing.

In the accompanying drawing, like characters indicate like parts.

Referring to the drawings:

Fig. l is a view in side elevation, with some parts in section and someparts broken away, of a preferred form of the invention; and

Fig. 2 is also a view in side elevation, with some parts broken away,but illustrating a somewhat modified form of the invention.

Description of Fig. 1

The main body of the device of Fig. 1 is in the nature of an elongatedcylinder, indicated as an entirety by 1. Preferably and as shown, thistubular body 1 comprises an elongated tubular shell 2 that is normallyclosed at its upper end by a readily displaceable cap 3 and at its lowerend by a supplemental body section 4, which is rigidly anchored to thesection 2 by screw threads or the like, as shown at 5. The axial bore ofthe elongated tubular section 2 of the body 1 serves as a reservoir 6for weed exterminating liquid, such, for example, as 2,4-D,dichlorophenoxyacetic acid, which may be supplied through the upper endof the body 1 upon removal of the displaceable cap 3. Preferably, and asshown, the displaceable cap section 3 is in the nature of an invertedcup of synthetic rubber or the like, which is telescopically appliedover the otherwise open end of the section 2 and is displaceably lockedin position by means of a spring wire bail 7, the trunnion-like ends 8of which pass through aligned apertures in the cap 3 and the upper endof the tubular body section 2. The bail 7 serves as a convenient meansfor hanging the device and is merely spread sufiiciently to withdraw theinturned ends 8 thereof from the tubular body 2 to allow displacement orapplication of the cap section 3.

The supplemental body section 4 has an axial bore 9, which serves as apump cylinder and is closed at its outer end and has its inner end inreceiving communication with the axially aligned bore 6 of the bodysection 2. The closed bottom end of the supplemental body section 4 isprovided with an axial plunger bore 10, which is of reduced diameterwith respect to the cylinder 9. An actuating plunger 11 works slidablythrough the bore 10 and carries at its inner end an expanded head 12,which serves as, and may be hereinafter referred to as, a pump piston.The pump piston 12 has normal free working clearance with the cylinderbore 9 and is normally yieldingly urged or biased downwardly to theextreme lower position shown in Fig. 1 by means of a coil compressionspring 13 having one end seated against the piston 12 and its other orupper end seated against an inturned flange or shoulder 14 of the bodysection 4.

In this embodiment of the invention, the piston 12 is provided with acircumferentially-spaced series of restricted flow passages or apertures15 extending therethrough to provide communication between the spacesabove and below the piston 12, the lower ends of these passages 15 beingdisposed radially outwardly of the plunger 11. A resilient annular valveelement 16 is disposed immediately adjacent the undersurface of thepiston 12 and is fixedly secured on the plunger 11 so as to movetherewith and the piston 12. It will be understood, however, that thisresilient valve element 16 is free of the piston 12 so that it is freeto flex upwardly and downwardly with respect thereto. In the preferredembodiment of the invention illustrated, the resilient valve element 16is in the nature of an axially perforated disc of rubber, syntheticrubber or the like, and is held or secured fast on the plunger 11 byfriction engagement therewith through its own resilience or elasticity.In other words, the central aperture or perforation of the resilientflexible and elastic valve element 16 is of less diameter than theplunger 11, so that a slight stretching of said valve element 16 isrequired to apply the same onto the plunger.

The upper end portion of the plunger 11 is provided with a central axialdischarge bore 17, which is closed at its upper end at 18 andcommunicates at its lower end with a circumferentially-spaced series ofdownwardly and outwardly directed final discharge orifices 19. The upperend portion of the axial flow orifice discharge passage 17 communicateswith a circumferentially-spaced series of radial fluid intake passages20, which, when the piston 12 is in its normal extreme lower positionshown, open into the upper end portion of plunger bore 10 just below theplane of the resilient valve element 16.

With this arrangement, upward movements of the plunger 11 and piston 12will be limited to a position wherein the discharge ends of thedownwardly and outwardly directed final discharge passages 19 are closed.by

being withdrawn slightly into the lower end of the plunger bore 10.Hence, with this arrangement, the cylinder space below the piston 12 andyielding valve seal 16 will be automatically closed against downwarddischarge during periods when the piston 12 is in its extreme upperpositions, so that there will be no appreciable loss of fluid underthese conditions.

Operation of Fig. 1

an undesirable weed or plant in a lawn or the like, he

places the end of the plunger 11 over the stem or center portion of thatplant and then exerts suflicient pressure on the upper end of thetubular body 1 to retract the piston 12 against the action of theyielding means or spring 13. During such upward or retracting movementsofthe piston 12, the pressure of the fluid in the reservoir 6 will beexerted against the yielding valve disc 16 and cause the same to flexdownwardly and permit fluid to flow thereby into the space in cylinderbore 9 below the piston 12. As soon as the piston 12 has been retracted,

the operator will relieve the downward pressure on the tubular body 1and permit the plunger-equipped piston 12 to be returned to its normalbottom position under the yielding action of spring 13. During thisreturn or relative downward movement of the piston 12, with respect tothe tubular body 1, the pressure below the resilient valve element 16,which now acts as a flap valve, will be greater than the pressurethereabove and will cause the said flap valve 16 to be pressed againstthe bottom of piston 12 and close ofl the passages 15, causing fluid tobe ejected through the fiow passages 20, 17 and 19. The fluid dischargedfrom the downwardly and outwardly-directed circumferentially-spacedpassages or orifices 19 will issue forth as a spray from eachsaid-orifice 19 to collectively produce a circular spray patternconcentric with the axis of plunger 11. The overall spray pattern thusproduced will be of sufi'icient overall diameter to assure ample wettingof the selected plant or weed to assure destruction thereof, but will bemildciently confined to prevent material damage to the as socia'ted'lawngrass. clover or the like. Of course, when the piston 12 again reachesits bot-tom extended position of the drawings, the valve disc 16 willagain be compressed between the piston and the end of the cylinder 9 tocompletely isolate the reservoir 6 from the discharge orifices orpassages 20. (In the device illustrated, no special means of venting thereservoir 6 to atmosphere has been shown, since it is assumed that therewill be sufiicient air leakage past the cap 3 to amply vent thereservoir to atmosphere.)

The device illustrated in Fig. 1 maybe made of any suitable metal orplastic material, but was particularly designed for fabrication formetal. When made of metal, it is desirable to make all metallic parts ofthe same metal, since the chemical 2,4-D and some other weed destroyingagents may set up electrolytic action between dissimilar metals, whichmay produce a rapid corrosion and consequent deterioration. Preferably,all of the elements of the device shown in Fig. l, with the exception ofthe cap 3 and the spring 13, are made of aluminum, and the spring 13 ismade of spring steel cadmium plated for protection.

Description of Fig. 2

The modified device of Fig. 2 may also be made from any suitablematerial, but was particularly designed for fabrication largely fromplastic parts, which may be inexpensively produced and is not subject toattack by chemical agents contemplated. The elongated tubular body ofthe device of Fig. 2 is indicated asan entirety by '21 and comprises anelongated tubular plastic shell 22 that is normally closed at its top'by :a displaceable plastic cap 23, equipped with a suitable bail 24. Nospecial means has been shown for detachably anchoring the "cap 23 to thetubular shell 22, but this may be accomplished "by any suitable means,such as friction fit, screw threads,

bayonet pins and slots, or other well-known means, allowing removal ofthe cap 23 for filling of the reservoir space 25 provided by the bore ofshell section 22. The lower end of the tubular shell section 22 isclosed by a supplemental shell section 26, which may also be of suitableplastic material and may be assumed to be permanently secured intelescopic engagement with shell section 22 by suitable cement or thelike at 27. Disposed in the lower portion of shell section 22 is aninverted cup-like element 28, which serves as a base of reaction or seatfor a coil compression spring 29 and is provided with a relatively largeaxial passage 30. The axial bore 31 of the supplemental shell section 26provides a pump cylinder. The closed outer end of shell section 26 isprovided with an axial plunger bore 32 of greatly reduced diameter withrespect to that of the cylinder bore 31. Working slidably through thisplunger bore 32 is a plunger 33, which may be made of any suitablematerial, but will preferably be metallic and may be assumed to be ofaluminum. The plunger 33 is provided at its inner end with a fixed headserving as a piston 34. In this form of the invention, there are nospecial passages, such as shown at 15 in Fig. 1, through the piston.However, suitable flow communication between the upper and lower sidesof the piston 34, during relative upward retracting movements of thesaid piston 34, is provided by a somewhat increased clearance betweenthe perimeter of piston 34 and the inner surface of cylinder 31. Thepiston 34 is yieldingly urged or biased toward its intended position ofFig. 2 by the compression spring 29, which is interposed therebetweenand the inverted cupshaped element 28.

In the form of the invention shown in Fig. 2, a resilient valve elementor seal 35 is provided and which is similar to the valve element 16 ofFig. 1 and is likewise anchored fast on the plunger 33 and lies flatagainst the under-surface of piston 34. To allow discharge of fluid fromthe cylinder 31, we reduce the diameter of the upper portion of plunger33, with respect to the plunger bore '32, so as to provide an annularflow passage 36 which communicates with a circumferentially-spacedseries of downwardly and outwardly directed final discharge orifices orpassages 37, which produce a spray pattern corresponding to the spraypattern produced by discharge through the orifices 19 of Fig. 1. In Fig.'2, the reduced diameter portion of the plunger 33, defining the innerwall of annular passage 36, is indicated by 36 and terminates at itslower end in .a shoulder 39 joining lllC same to the maximum diameterportion of the plunger 33. In the arrangement of Fig. 2, upward chargingmovements of the piston 34 and plunger 33 are limited by engagement ofpiston 34 with a stop shoulder 40; the design being such that the innerends of the final discharge passages 37 will be covered and closed bythe maximum diameter portion of the plunger 33 when the piston is in itssaid upper extreme position against stop shoulder 40, so as 'to preventdownward discharge of fluid when "the piston is in its said upperposition.

Operation of Fig. 2

The manner of operation of the device of Fig. 2 is identical to thatdescribed .in connection with Fig. l, insofar as handling by theoperator is concerned. However, when the piston 34 of Fig. 2 partakes ofrelative upward movement with respect to the tubular body 21, the fiowof fluid .from the space above to the space below the piston 34 will bearound, ,rather than through, the piston 34 and will be sufficientlyrapid .to completely fill the space below the piston 34 under normalrelatively slow upward movements .of the piston .34 under manualpressure. However, when manual pressure is released, the spring .29 willtake over and :move the piston 34 downwardly with sufficient speed .toproduce ample discharge pressure below the piston 34, even in thepresence of considerable 'backflow through the generally annular flowpassage clearance '38 between the piston .34- and cylinder bore 31. Inother words, the pump will be designed to produce the desired volumetricdischarge through passages 36 and 37 in the presence of thepredetermined backflow past piston 34. During return strokes of thepiston 34 under the action of spring 29,

"fluid will be discharged from .orificcs 37 onto the leaves of theoffending plant'or weed exactly as described in connection with Fig. l.Of course, when the piston 34 reaches the bottom of its stroke, thevalve element or seal 35 will be compressed between the piston 34 andthe closed end of shell element 26 and will positively cut off flowthrough the annular passage 36 and circumferentially-spaced dischargepassages 37.

Our invention has been thoroughly tested and found to be completelysatisfactory for the accomplishment of the objectives set form; andwhile we have shown a commercial embodiment of our improved device itwill be understood that the same is capable of modification withoutdeparture from the scope and spirit of the invention as defined in theclaims.

What we claim is:

1. In a liquid dispenser, an elongated tubular body member, one end ofsaid member defining a liquid reservoir and the other end thereofdefining a pump cylinder, an axial passage providing continuouscommunication between said reservoir and said pump cylinder, said otherend of said body member terminating in a reduced elongated tubularportion having an axially disposed plunger bore therein, a plungerhaving a reduced inner end of less diameter than its outer end slidablymounted in said plunger bore and working between an inner closureposition, and an outer closure position, said reduced inner endproviding an annular space between said inner end and said plunger bore,a pump piston head fixed to the reduced diameter inner end of saidplunger and disposed Within said pump cylinder, said piston head beingof substantially less diameter than the diameter of the pump cylinderproviding a flow passage between the inner and outer pump cylinderchambers on opposite sides of the piston head during the workingmovements thereof, a generally outwardly directed restricted dischargepassage communicating with said annular space providing selectivedischarge from said outer cylinder chamber, a resilient annular valveseal fixed to the reduced end of the plunger against the outer surfaceof the piston head and movable therewith, said piston head and saidvalve seal cooperating to close communication between said pump cylinderand discharge passage when said plunger is in said outer closureposition, said outer end of sald plunger closing communication betweensaid pump cylinder and discharge passage when said plunger is in saidinner closure position, said communication between said pump cylinderand said discharge passage being open when said plunger is intermediatesaid inner and outer closure positions, and resilient spring meansnormally urging said plunger to said outer position.

2. The structure defined in claim 1, wherein said elongated tubular bodymember comprises an elongated tubular shell, a displaceable cap elementremovably secured to and normally closing said one end, a secondsupplemental shell telescopically secured to and closing said other end,an inverted cup-like element having said axial passage therein, disposedintermediate said first shell and said supplemental shell, said capelement, first shell and cup-like element defining said reservoir, andsaid cup-like element and said supplemental shell defining said pumpcylinder.

3. In a liquid dispenser, an elongated tubular body structure comprisingan elongated tubular shell, a displaceable closure element removablysecured to and normally closing one end of said tubular body structure,a supplemental second shell telescopically secured to and closing theother end of the tubular body structure and terminating in a reduceddiameter elongated tubular portion having an axially disposed plungerbore therein, an inverted cup-like element disposed adjacent thejunction of the first and second said shells and having a portiondisposed therebetween and having an open restricted passageway therein,said closure element and first shell and cup-like element defining aliquid reservoir, said cuplike element and said second shell defining apump cylinder, a plunger and piston assembly comprising a plungerslidably mounted in said plunger bore and working between an innerposition and an outer closure position and a pump piston head fixed tothe inner end of the plunger and disposed within the pump cylinder, saidpiston head being of substantially less diameter than the diameter ofthe pump cylinder and defining a flow passage between the inner andouter pump cylinder chambers on opposite sides of the piston head duringworking movements of the piston, a generally outwardly directedrestricted discharge passage through the second shell from the outerpump cylinder chamber and located radially outwardly of the plunger toprovide selective discharge from said outer cylinder chamber, theplunger and piston assembly defining an annular valve seal surroundingthe extreme inner end of the plunger and movable therewith to seatagainst said second shell radially outwardly of the opening of saidrestricted discharge passage from the outer pump cylinder chamber andclosing communication between said pump cylinder and discharge passagewhen said plunger is in said outer closure position, said communicationbetween said pump cylinder and said discharge passage being open whensaid plunger is intermediate said inner position and said outer closureposition, and resilient spring means normally urging said plunger tosaid outer position.

References Cited in the file of this patent UNITED STATES PATENTS Re.13,898 Morrill Apr 6, 1915 1,046,408 Voges Dec. 3, 1912 1,165,673 HolmesDec 28, 1915 1,251,288 Rogers Dec 25, 1917 1,586,398 Bobrick May 25,1926 1,699,237 Goldrick Jan. 15, 1929

